The invention pertains generally to an energetic gas producing composition and in particular to liquid propellants.
A liquid propellant is one which is introduced into the combustion chamber as a liquid. The term includes all the liquids which may be used in a propellant composition, such as, fuel, oxidizer, catalyst, and other additives. If the fuel and oxidizer are separate compounds, the propellant is termed a bipropellant and if a compound does not require an oxidizer to release its thermal nuclear energy the compound is termed a monopropellant.
An important group of monopropellants consists of nitrated organic compounds, which unfortunately are unstable. These monopropellants have many of the usual liquid propellant advantages, e.g., a greater total impulse, better thrust control and firing determination, longer firing time, and simpler manufacturing. A major disadvantage of these propellants, which severely limits their uses, is their sensitivity.
In order to desensitize these compounds a diluent or a desensitizing agent is usually added to the compound. The most successful liquid propellant to date has been the Otto fuel which was disclosed and claimed in U.S. Pat. No. 4,026,739 issued to Otto Reitlinger. This composition utilizes di-n-butyl sebacate (DBS) as a diluent for 1,2 propylene glycol dinitrate (PGDN) with 2-nitrodiphenylamine as a stabilizing agent. The composition in U.S. Pat. No. 3,634,158 by Albert T. Camp and Paul R. Mosher utilizes metriol trinitrate as an energetic diluent for triethylene glycol dinitrate, included also in the composition is a common storage stabilizer, for instance, ethyl centralite. In U.S. Pat. No. 3,116,188 of Theodore D. Austin, an aliphatic polybasic acid ester, such as, tributyrin (C.sub.3 H.sub.7 COO).sub.3 C.sub.3 H.sub.5 or tricaproin (C.sub.5 H.sub.11 COO).sub.3 C.sub.3 H.sub.5 is used as a desensitizing agent for liquid nitrate esters, such as, nitroglycerin or ethylene glycol dinitrate. The composition, with the lowest sensitivity, utilizes di-n-buty sebacate (DBS) and is disclosed in U.S. Pat. No. 4,026,739. However this composition has the major disadvantage of having an extremely high viscosity at temperature below 0.degree. C. and a glass transition temperature of about -32.degree. C. These disdavantages cause the use of this composition to be restricted to uses at temperatures above 0.degree. C., for example, torpedo propellant.